Greg, I can't tell if this is the same thing or not, but there was an episode of Ask This Old House where Tom Silva used something that looked like this. The screws would go in, then you snap them off just below the subsurface so that you couldn't feel anything walking on them even barefooted. He was sold on it, if this is indeed the same thing. Jim.
Home of Irish Setter Rescue of North Texas
When Irish Eyes are smiling, they're usually up to something!!
At a minimum, I'm Pentatoxic...but most likely, I'm a Pentaholic. There seems to be no known cure. Pentatonix, winners of The Sing Off, season 3